Outline of research methodology in.pptx

Research
Finding
Thesis

1. Outline Introduction to Research Types of research Topic selection Analysis statement of the problem Literature review Objectives Research methods Work plan and budget

2. Introduction to Research Definition Research is a scientific inquiry aimed at learning new facts, testing ideas, etc. It is the systematic collection, analysis and interpretation of data to generate new knowledge and answer a certain question or solve a problem. Objectives of Research To gain familiarity with a phenomena or to gain new insight into it To portray accurately the characteristic of a particular cause, situation or environment 

3. To determine the frequency with which something occurs To determine the relationship between two or more variables To ascertain causes and effect relationship To test hypothesis Why do we need research? Satisfaction of curiosity Save human life/to reduce suffering Correct judgment/decision Problem finding or solving Excellence Improvement

4. Criteria for a good research question (FINER) Feasible (F ) Adequate number of subjects Adequate technical expertise Affordable in time and money Manageable in scope  Interesting to the investigator (I) Novel Confirm or refutes previous finding Extends previous finding Provides new finding Ethical

5. Relevant To scientific knowledge To clinical and health policy To future research directions

6. Research process Step one Define research problem Step two Review of literature: Review theory and concept Review provisional research findings Step three Selection of research title and make plan Understand what you are being asked to do and define your topic to meet the requirements of your assignment:

7. Understand the assignment Find a topic and brainstorm ideas Narrow and /or broaden the topic as necessary Draft the thesis statement Step four Formulation of hypothesis Step five Design research (including sample design) Collect data Analyze data (test hypothesis if in by using statistical tools) Step six Interpret results

8. TYPES OF RESEARCH The basic types of research are as follows: Descriptive vs. Analytical: Descriptive research includes surveys and fact-finding enquiries of different kinds. We quite often use the term Ex post facto research for descriptive research studies. The methods of research utilized in descriptive research are survey methods of all kinds, including comparative and correlation methods. In analytical research , on the other hand, the researcher has to use facts or information already available, and analyze these to make a critical evaluation of the material.

9. Applied vs. Fundamental : Research can either be applied (or action) research or fundamental (to basic or pure) research. Applied research aims at finding a solution for an immediate problem facing a society or an industrial/business organization F undamental research is mainly concerned with generalizations and with the formulation of a theory. “Gathering knowledge for knowledge’s sake is termed ‘pure’ or ‘basic’ research.”

10. Quantitative vs. Qualitative Quantitative research is based on the measurement of quantity or amount. It is applicable to phenomena that can be expressed in terms of quantity. Qualitative research, on the other hand, is concerned with qualitative phenomenon, i.e., phenomena relating to or involving quality or kind. For instance, when we are interested in investigating the reasons for human behaviour (i.e., why people think or do certain things), we quite often talk of ‘Motivation Research’, an important type of qualitative research.

11. Conceptual vs. Empirical Conceptual research is that related to some abstract idea(s) or theory. It is generally used by philosophers and thinkers to develop new concepts or to reinterpret existing ones. Empirical research relies on experience or observation alone, often without due regard for system and theory. It is data-based research, coming up with conclusions which are capable of being verified by observation or experiment.

12. Some Other Types of Research Based on either the purpose of research One-time research Longitudinal research Field-setting research or laboratory research

13. Problem identification Research problem is the uncertainty about something in the population that the investigator wants to resolves by making measurements on his study subjects Whether a problem requires research depends on three conditions: There should be a perceived difference or discrepancy between what it is and what it should be;

14. The reason(s) for this difference should be unclear (so that it makes sense to develop a research question); and There should be more than one possible and plausible answer to the question (or solution to the problem). Example1: Problem situation: In district “ Y “ a report showed that in the first month there were 500 children under one year old who started immunization, but at the end of the year it was found out that there were only 25 children who completed their vaccination.

15. Discrepancy: All the 500 children at district “Y “should have completed their vaccination but only 5% out of those who started vaccination has completed. Problem (research) question : why only 5% of the children completed their vaccination? Definite answer: Out of the 1 hospital, 2 health centers and 10 health stations found in district “Y” only 2 health stations were functioning, the rest were closed due to insecurity in the area. In the above example, assuming that all the given facts are true, there is no need of undertaking a research, since definite answer is obtained to the problem situation.

16. Selecting a problem An overdone subject should be avoided Too narrow or too vague problems should be avoided Controversial problems should not be selected The qualification of researcher, training obtained, cost involved, time factors and practicability of the finding for societal use and benefit should be given due importance Elements of good research problems If one wants to solve the problem one must generally know what the problem is. It should be clear , unambiguous with very little confusion

17. it must to try to find out the relationship between two or more variables It should be empirically measurable Formulating the problem statement After identifying, selecting and analyzing the problem, the next major section in a research proposal is “statement of the problem” Because a clear statement of the problem: Is the foundation for the further development of the research proposal (research objectives, methodology, work plan, etc); Makes it easier to find information and reports of similar studies from which your own study design can benefit;

18. Analysis and statement of problem A systematic analysis of the problem, completed jointly by the researchers, health workers, managers, and community representatives is a very crucial step in designing the research because it: Enables those concerned to bring together their knowledge of the problem, Clarifies the problem and the possible factors that may be contributing to it, Facilitates decisions concerning the focus and scope of the research.

19. Enables the researcher to systematically point out why the proposed research on the problem should be undertaken and what you hope to achieve with the study results Points that need to be considered for justifying the selected research problem A health problem selected to be studied has to be justified in terms of its: Being a current and existing problem which needs solution Being a widely spread problem affecting a target population Effects on the health service programmes Being a problem which concerns the planners, policy makers and the communities at large

20. Literature review The review of already available information or already existing knowledge regarding the research interest is known as literature review Use of literature review It prevents you from duplicating work that has been done before. It increases your knowledge on the problem you want to study and this may assist you in refining your "statement of the problem". It gives you confidence why your particular research project is needed. To be familiar with different research methods

21. Sources of information Card catalogues of books in libraries Organizations (institutions) Published information (books, journals, etc.) Unpublished documents (studies in related fields, reports, etc.) Computer based literature searches such as Medline Opinions, beliefs of key persons Some examples of resources where information could be obtained are:

22. Clinic and hospital based data from routine activity statistics Local surveys, annual reports Scientific conferences Statistics issued at region and district levels Articles from national and international journals Internet Documentation, reports, and raw data from the Ministry of Health, Central Statistical Offices, Nongovernmental organizations, etc

23. Objectives The expected solution of the problems are the objectives of the study. Objectives should be closely related to the statement of the problem. For example, if the problem identified is low utilization of health stations in a rural district, the general objective of the study could be to assess the reasons for this low utilization. If we break down this general objective into smaller and logically connected parts, then we get specific objectives.

24. Definition General objectives: aim of the study in general terms Example: In a study on missed opportunities for EPI in Nepal the general objective is: “to assess missed opportunities for EPI in Nepal”. Specific objectives: measurable statements on the specific questions to be answered. Unlike the general objectives, the specific objectives are more specific and are related to the research problem situation. They indicate the variable to be examined and measured.

25. Example: In the study of missed opportunity for EPI in Nepal the specific objectives could be: To find out the magnitude of missed opportunities for children who attend OPD, MCH, etc. in Nepal, To examine the reasons for children not being immunized while attending the OPD, MCH, etc. services. Formulation of the research objectives The formulation of objectives will help us to: Focus the study (narrowing it down to essentials)

26. Avoid collection of data that are not strictly necessary for understanding and solving the identified problem Organize the study in clearly defined parts How should we state our objectives? We have to make sure that our objectives: Cover the different aspects of the problem and its contributing factors in a coherent way and in a logical sequence Are clearly expressed in measurable terms Are realistic considering local conditions Meet the purpose of the study Use action verbs that are specific enough to be measured

27. Examples of action verbs are: - to determine to compare to verify to calculate to describe to find out to establish Avoid the use of vague non-action verbs such as; to appreciate to understand to study to believe

28. study designs A study design is the process that guides researchers on how to collect, analyze and interpret observations. It is a logical model that guides the investigator in the various stages of the research. Several classifications of study types are possible, depending on what research strategies are used Types of study designs

29. Non-intervention (Observational) Studies in which the researcher just observes and analyses researchable objects or situations but does not intervene; and Intervention studies The studies in which the researcher manipulates objects or situations and measures the outcome of his manipulations (e.g., by implementing intensive health education and measuring the improvement in immunization rates.)

30. Study designs could be exploratory, descriptive or analytical Exploratory studies An exploratory study is a small-scale study of relatively short duration, which is carried out when little is known about a situation or a problem. It may include description as well as comparison. Descriptive studies: Descriptive studies may be defined as studies that describe the patterns of disease occurrence and other health-related conditions by person place and time.

31. Personal variables include : Basic demographic factors, such as age, sex marital status or occupation, as well as the consumption of various types of food or medication use. Characteristics of place refer to the geographic distribution of disease , including variation among countries or within countries, such as between urban and rural areas. With regard to time, descriptive studies may examine seasonal patterns in disease onset etc.   Uses of descriptive studies   They can be done fairly quickly and easily. Allow planners and administrators to allocate resources Provide the first important clues about possible determinants of a disease (useful for the formulation of hypotheses)  

32. Types of descriptive studies Case reports and case series  Case report: a careful, detailed report by one or more clinicians of the profile of a single patient. The individual case report can be expanded to a case series, which describes characteristics of a number of patients with a given disease. Uses Important link between clinical medicine and epidemiology One of the first steps in outbreak investigation Often useful for hypothesis generating and examining new diseases, but conclusions about etiology cannot be made.

33. Ecological studies: data from entire populations are used to compare disease frequencies between different groups during the same period of time or in the same population at different points in time. Example: Countries with low cigarette consumption have lower lung cancer rates than those countries with high cigarette consumption.  Ecological studies are usually quick and easy to do and can be done with already available information. Since ecological studies refer to whole populations rather than to individuals, it is not possible to link an exposure to occurrence of disease in the same person.

34. Cross-sectional studies A cross-sectional (prevalence) study provides information concerning the situation at a given time. In this type of study, the status of an individual with respect to the presence or absence of both exposure and disease is assessed at the same point in time. Usually involve collection of new data. In general, measure prevalence rather than incidence Not good for studying rare diseases or diseases with short duration; also not ideal for studying rare exposures

35. Analytical study Studies used to test hypotheses concerning the relationship between a suspected risk factor and an outcome and To measure the magnitude of the association and its statistical significance. Analytic study designs can be divided into two broad design strategies: Observational and intervention.   Observational studies No human intervention involved in assigning study groups; simply observe the relationship between exposure and disease.

36. Subject to many potential biases, but by careful design and analysis, many of these biases can be minimized. Examples of observational studies: comparative cross-sectional, cohort and case control Studies. Comparative cross-sectional studies: Depending on the purpose of a given study, a cross-sectional survey could have an analytical component Cohort studies: Study groups identified by exposure status prior to ascertainment of their disease status and both exposed and unexposed groups followed in identical manner until they develop the disease under study, they die, the study ends, or they are lost to followup .

37. Strengths and limitations of the cohort study design Strengths: Is of particular value when the exposure is rare Can examine multiple effects of a single exposure Allows direct measurement of incidence of disease in the exposed and non-exposed groups. Limitations: Is inefficient for the evaluation of rare diseases Expensive and time consuming Validity of the results can be seriously affected by losses to follow-up.  

38. CASE CONTROL OR CASE HISTORY STUDY

39. Case-control studies Group of subjects with the disease (cases) and group of subjects without the disease (controls) are identified. Information, about previous exposures are obtained for cases and controls, and frequency of exposure compared for the two groups. Strengths and limitations of the case-control study design Strengths: Is relatively quick and inexpensive Is optimal for the evaluation of rare diseases. Can examine multiple etiologic factors for a single disease.  

40. Limitations:  Is inefficient for the evaluation of rare exposures Cannot directly compute incidence rates of disease in exposed and non- exposed individuals. Is particularly prone to bias compared with other analytic designs, in particular, selection and recall bias.

41. Intervention studies In intervention studies, the researcher manipulates a situation and measures the effects of this manipulation. Usually (but not always) two groups are compared, one group in which the Intervention takes place (e.g. treatment with a certain drug) and another group that remains ‘untouched’ (e.g. treatment with a placebo). The two categories of interventions are:

42. Experimental studies Quasi-experimental studies Experimental studies It gives the most reliable proof for causation Individuals are randomly allocated to at least two groups. One group is subject to an intervention, or experiment, while the other group(s) is not The outcome of the intervention (effect of the intervention on the dependent variable/problem) is obtained by comparing the two groups. These are widely used in laboratory settings and in clinical settings

43. Quasi-experimental studies one characteristic of a true experiment is missing, either randomization or the use of a separate control group One of the most common quasi-experimental designs uses two (or more) groups, one of which serves as a control group in which no intervention takes place? Both groups are observed before as well as after the intervention, to test if the intervention has made any difference. (This quasi-experimental design is called the ‘non-equivalent control group design because the subjects in the two groups (study and control groups) have not been randomly assigned

44. Ethical considerations   Defined as the act of moral principles which the researcher has to follow while conducting the research to ensure the right and welfare of individuals, group or community under the study Why do we need ethical approval? But history shows us that prior to the development of ethical and human rights over the last 40 years, patients’ rights were often ignored and many individuals were seriously harmed by medical experimentation.

45. Atrocities committed during World War II in the Nazi Germany which led to the 1947 Nuremberg Code of Practice and in turn the 1964 Declaration of Helsinki Tuskegee Syphilis Study in USA (1932-1970s) to study the long-term effects of untreated syphilis- 400 men out of the 600 participants were never told about the infection and were never treated despite the fact that treatment became available A study to examine the natural progression of cervical carcinoma in New Zealand (1980s)-conventional treatment was withheld from women in trial and women were not asked for their consent  

46. Research studies should be judged ethically on three sets of criteria, namely: ethical principles, ethical rules, and scientific criteria . Ethical principles Autonomy- we ought to respect the right to self-determination Non- Maleficence - we ought not to inflict evil or harm  Beneficence – we ought to further others’ legitimate interests Justice-we ought to ensure fair entitlement to resources 

47. Ethical rules Veracity All subjects in any research project should always be told the truth. Privacy No revelation of information that could identify the subject or organization Follow –up code rather than name Confidentiality No information obtained with the patient’s or subject’s from permission their medical records should be disclosed to any third person without that individual’s consent.

48. Fidelity Fidelity means keeping our promises and avoiding negligence with information. Applying to ethics committee Remember that the key questions that the Ethics Committee will be asking are: Is the research valid? How important is the research question? Can the question be answered?

49. Is the welfare of the research subject under threat? What will participating involve? Are the risks necessary and acceptable? Is the dignity of the research subject upheld? Will consent be sought? Will confidentiality be respected?  

50. Data Source and Collection Technique Data is the foundation of all field work project Data should be reliable and correct Source of data/information to be collected are two types Primary data Secondary data Primary data can be collected by Observation method Interview Information from local correspondents Questionnaires and shedules

51. Data management and analysis The quality of the out come of research depends on the data. It should be noted that the following are essential for the data Accuracy modifies the result Time lineness is needed for data verification and validation Planning is also necessity’ Completeness of the data facilitates in processing and analysis Conciseness of the data helps in data handling and computation Relevancy improves the results

52. Research proposal writing

53. Research proposal Definition Written document specifying what the investigator purpose It is written before the project has commenced In the academic institution the research proposal is commonly known as synopsis Purposes of a research proposal Provide an opportunity to the researcher and expert to think project carefully and clarity and define what exactly to study It serves as a blue print and guiding path for the researcher to carry out the research project Helps the researcher to communicate to the supervisor faculty or funding agency

54. Format of research proposal A research proposal usually consist of the following elements Title Make the title concise, specific and descriptive Short title are clear and more interesting Limit one or two lines Avoid excessive adjective and noun strings Be careful of syntax Use scientific name of organisms Name and address of PI and Co-PI Full name, qualification, academic title of the institute and their institute

55. Abstract Abstract is often the first things read by the reviewer: The abstract should contain the essence of the whole purposal in 2-3 sentence and should stand alone It should consist of 3 basic parts Why is the study to be done? What is to be done How will it be done

56. Body of the proposal Introduction/rationale and justification One or two paragraphs should explains the background Review relevant the literature (5-10 yrs period) Rationale and justification Statement explaining why the researcher feel the research project is important and therefore be carried out It should not be more than one or two paragraphs

57. Aims and objectives What is the point of the study? Give overall aim of the project in one sentence Give the specific objectives which are breakdown of the general objectives Methods It is your guide on how the study will be done as well as the data analysis It includes: Type of the study design Location of the study Study population Study period

58. Sample size Data collection Data analysis Ethical consideration Limitation of the study mention the things that you want but could not involve in your study Expected out come Time line

59. Activities Apr May Jun July Aug Sept Oct Nov Dec Jan Feb Mar 1. Draft proposal x 2.Finalize proposal x 3.Finalize data collection instrument and pre-testing x 4. study area visit x 5. Recruitment of data collectors and supervisors x 6. Logistic arrangement x 7.Training of Survey co-ordinator x 8.Ttraining of supervisiors and enumerators x 9. Socio-Demography Survey x x x 9. Sero Survey x x x 10. Field supervision x 11. Data entry x 12. Verification of data x 13.Data analysis x 14 .Report writing x

60. Budget justification References All relevant references must be listed in alphabetic order Annexes This section consist of questionnaires, maps and photos etc Enclose the researchers curriculum vitae and list the publication related to the project

61. Thesis/report writing

62. Thesis/Report writing The research works carried out by students are often known as project work. These works are done as part of curriculum for academic degrees known by different names such as dissertation, thesis, Field report Format of the Thesis/Report A research report should be written in a standard format. It consist of three major parts The preliminary page The main text And The end text 

63. Preliminary pages (Under page numbers, with Roman numerals i.e., I, II, II, IV, etc) It includes: Cover page- with title, name of the department/institution for the thesis to be submitted and the name of the submitter Declaration by the candidate Recommendation letter from the supervisor Letter of approval from the Department Head Certificate of approval from the evaluation committee Acknowledgements Table of contents List of tables List of figures Acronyms Abstract

64. Introduction State the brief back ground of the study Give the statement of the problem Give the purpose of the study and rational /Justification Give the statement of hypothesis, aims and objectives of the study  Give only strictly pertinent reference (don’t review extensively) Do not mention the data or conclusion from the study being reported

65. Literature Review Accurate , relevant ,useful, reliable and latest information should be filtered from all available literature The review of literature must mention the name of the researcher, what and when the work was done/published and its major finding Materials and Methods describe the selection of the observational or experimental subject clearly Identify the methods, apparatus and procedure in sufficient in details Give the reference to established method Describe the statistical methods utilized for data analysis

66. Results Present results in a logical sequence in the text, tables and figures The results should contain an explanation and description of the data, and highlight of the finding , patterns , trends or relationship observed Analyze your data by statistical means Discussion and conclusion The discussion includes analysis and interpretation of the main findings of the investigation, comments and conclusion based upon the finding relation of the finding to the other relevant studies through literature

67. Do not repeat in detail the data that have given in the introduction or result section Includes the implications of the finding and their limitation as well as implication for future research Link the conclusion with the goals of the study but avoid unqualified statement and conclusion not completely supported by your data Recommendation This section includes the researcher’s suggestions for the further research or for the development of society Recommendation are based on the result of the study

68. Reference/Citation of literature Follow your department guideline End matter/Supplement part This includes: Appendix It can include raw data ,questionnaires, photo plate etc which are the supporting documents of your research work

69. Writing a Scientific Paper: Basics of Content and Organization

70. Definition of a Scientific Paper The first publication of original research results The paper should be prepared according to the guideline provided by the journal editors. The given steps must be documented in a clear and simple language

71. The IMRAD Format for Scientific Papers I ntroduction: What was the question? M ethods: How did you try to answer it? R esults What did you find? D iscussion What does it mean?

72. The Front Matter Title Authors Abstract

73. Title The fewest possible words that adequately indicate the contents of the paper Important in literature searching Should be specific enough but not overly narrow Authors Those with important intellectual contributions to the work Often listed largely from greatest contributions to least Head of research group often is listed last Mention the present affiliation of authors

74. Abstract Summarizes the paper Widely read and therefore important Commonly organized in IMRAD format (may be structured abstract, with headings corresponding to the various sections) Maximum length of 300 words for a full length of articles Key words Up to five words should be provided at the bottom of the abstract for computer search or library search in the future

75. The Core of the Paper Introduction Methods Results Discussion Conclusion

76. I ntroduction Include background of the work General and specific goal of the research Typically should be funnel-shaped, moving from general to specific. Materials and methods Purposes: to allow others to replicate and to evaluate what you did Should describe the study design Should identify (if applicable) Equipment, organisms, reagents, etc used (and sources thereof) Approval of human or animal research by an appropriate committee Statistical methods

77. Results The core of the paper Often includes tables, figures, or both An issue: how much the information in the text should overlap with that in the tables and figures Should present results but not comment on them

78. Discussion Often should begin with a brief summary of the main findings Should answer the question stated in the introduction Some other items commonly addressed: Limitations of the study Relationship to findings of other research Other research needed Typically should move from specific to general (opposite of introduction) Conclusion Indicate the usefulness and importance of the work relevant to future research and its application

79. End Matter Acknowledgments References

80. Acknowledgments A place to thank people who helped with the work but did not make contributions deserving authorship Permission should be obtained from people you wish to list Sometimes the place where sources of financial support are stated

81. Referencing What is referencing? Referencing is a standardized method of acknowledging sources of information and ideas that we have used in our assignment , in a way that uniquely identifies their source. Both published and unpublished work must be referenced Vancouver system is mostly used Reference : It contains details of only those works cited in the text Bibliography: if relevant sources that are not cited in the text are included, the list is called a bibliography.

82. How to write reference in the text Use last name If two authors, use “and” in between Mention family name of one author in the text For more than three authors, mention first author’s family name and write et al. After authors name, use comma(,) and mention the publication year. Examples More than 95% of American and Indian populations with diabetes have type 2 diabetes (Zimmer,1982) as many as 58% of the patients reported having no history of seizure had abnormal EEG ( Shrestha et al., 2004)

83. How to create a reference list? Example of the type of printed references Chapter in book Bibliography details are arranged in the sequences: Author of chapter (Full last name, initial of 1 st and 2 nd name) Chapter title Title of book Edition of the book Place of publication Publisher Year of publication Chapter pages

84. Chapter in book: Phillips SJ, Whsinant JP. Hypertension and stroke. In : Laragh JH, Brenner BM.Hypertension : Pathophysiology,diagnosis and management.2 nd ed.New York:Raven press; 1980 Book Author name Title book Edition of book Place of publication Publisher Year of publication Page number

85. Book with a personal author Ringsven MK, Bond D. Gerentology and leadership skills for nurses.2 nd ed. Albany(NY): Delmar Publishers;1996. Book with editor as author Norman IJ, Redfern SJ,editors . Mental health care for elderly people . New York: churchill Livingstone; 1996 Organization as author and publisher Institute of medicine (Nepal) . Look in at the future of the medical program. Kathmandu : the istitute;1992

86. Scientific technical report Scientific or technical report Smith P. Golladay K. payment for durable medical equipment billed during skilled nursing facility stays. Final report. Department of Health Service, Nepal,1994. Dissertation Dhungana J. Tuberculosis and HIV co.infection in patients attending Tansen Hospital, Palpa (dissertation). Central Department of Microbiology, Tribhuvan university, kathmandu;2002 Journal article Author of journal article Article title Journal title abbreviation Date of publication Volume of journal Issue of journal Article pages

87. Standard journal articles (1to6) authors Vega KJ, Pina I, Krevsky B. Heart trasplant is associated with an increased risk of pancreatobility disease. Ann intern Med 1996;124:980-3. Journal article (no author) Cancer in South Africa (editorial ). S Afr Med J 1994; 84:15 Journal article (organization as author) The cardiac society of Australia and New Zealand . Clinical exercise stress testing , safety and performance guidelines. Med j Aust 1996;164:282-4

88. Example of type of electronic references Journal articles Author of journal articles Article title Journal title abbreviation Type of medium (use “electronic” if you are unsure if it is online or networked CD –ROM) Date of publication Cited date Volume of journal Issues of journal Article page or indication length “Available” statement : supplier/database name/identifier number if available/item or accession number.

89. Morse SS. Factors in the emergence of infectious disease. Emerg infect Dis( Serial online) 1995 Jan-March (cited 1990 Jun 5); 1 (1): (24 screens). Available from: URL: http://www.cdc.gov/ncidod?EID/eid.htm

90. Epidemiology

91. Concept of epidemiology Epidemiology is the study of the occurrence, and determinants of the health problems and diseases in human population or communities and use of the knowledge for the prevention, control and treatment of the disease. The primary unit of the study in epidemiology is a group of person not any single person The word “Epidemiology “is derived from the Greek word epidemic Epi : on, upon, to Demos: people Logos: knowledge, doctrine, discourse, science

92. Epidemiology is a multi-disciplinary subjects involving those of Physician Biologist Public health expert Infectious disease expert Dentist Veterinarians Public health experts Infectious disease experts Nutritionists Health educators Social workers Anthropologist Biochemist

93. History of epidemiology History of epidemiology goes back to Hippocrates (400BC) through John snow (1800BC) and others Hippocrates (400BC) attempted to explain disease occurrence from rational instead of supernatural view point John Graunt published his land mark analysis of mortality data in 1662 William Farr began to systematically collect and analyze Britain’s mortality statistic Considered him as father of modern vital statistics Dr. John Snow conducted his classical study in 1854 when an epidemic of cholera developed in the golden square of London

94. History Map of Cholera outbreaks in London During the 196 and early 1970 health worker applied epidemiological method to eradicate small pox world wide0

95. Aims of epidemiology According to the International Epidemiological association (IEA), epidemiology has three main aims: To describe and analyzes disease occurrence and distribution in human population To identify a etiological factors (risk factors) in the pathogenesis of disease and To provide essential data to the planning, implementation and evaluation of services for the prevention, control and treatment of the disease and to the setting of priorities among those services

96. Fields of epidemiology Geographic epidemiology Spatial distribution of disease Social epidemiology Social determinants and their influence on the determination of the health situation of population Clinical epidemiology Clinical understanding for proper identification of the disease Statistical epidemiology Research design and analysis Establishing relationship between cause and effect

97. Descriptive epidemiology and field survey To determine the point prevalence To find the causation of the disease Analytical epidemiology To determine the incidence To find the causal relationship Experimental Epidemiology Experimentation to explore principle of the disease occurrence, prevention and control Infectious disease epidemiology To develop proper control measures Preventive practice to avoid out break

98. Administrative , prevention and control and treatment of the diseases Emergency management Uses of epidemiology Investigation of causation of disease Study of natural history and prognosis of the diseases Description of health status of population Evaluation of the health intervention and health program Planning health services, public policy and program To study the working of health services, determination of needs and resource, proceed for analysis of services in action

99. Epidemiological methods

100. CORRELATIONAL

101. Screening The process, by which unrecognized disease or defects are identified by test that can be applied rapidly on a large scale is known as screening Screening sorts out healthy people from those whom may have disease Types of screening Mass screening: Screening of a whole population Multiphase screening: use of a variety of screening test on the same occasion Target screening: it involves screening of specific group Case finding: it is restricted to patients who consult a health practitioner for some other purpose

102. Screening, examples Women receive regular screening tests beginning in young adulthood for cervical cancer (Pap smear ) Physicians assess blood pressure and cholesterol as screening tools for the development of cardiovascular disease Women use home pregnancy tests to screen for presence of an embryo or fetus

103. Basic feature of screening program Aspect Requirement Disorder Well defined Prevalence Known Natural history Medical important disorder for which there is an effective remedy available Financial Cost-effective Facilities Available or easily instilled Ethical Positive result generally agreed and acceptable Test Simple and safe Test performance Overlapping small and suitable cut off value defined

104. Screening test evaluation Sensitivity Specificity Positive predictive value Negative predictive value

105. Terms Definition Sensitivity Ability of the test to give positive results in a group of persons with the disease or probability of a positive test in people with the disease Specificity Ability of the test to give a negative results in a group of person without disease or probability of a negative test in people without the disease Predictive positive value Probability of the persons having disease when the test is positive Predictive negative Value Probability of the person not having the disease when the test is negative

106. Screening test evaluation

107. Screening test evaluation Assess sensitivity and specificity to understand the proportion of diseased and non-diseased individuals correctly categorized as diseased and non- diseased Assess PPV and NPV to understand the proportion of positively screened and negatively screened individuals that have disease or are disease- free

108. ERRORS IN EPIDEMIOLOGICAL STUDIES

109. ERROR Is defined as a false or mistaken result obtained in a study or experiment Consists of 2 components Systematic error Random error

110. RANDOM ERROR Refers to fluctuations around a true value because of Sampling variabilit y SYSTEMATIC ERROR Any difference between the true value and that actually obtained that is the result of all causes other than Sampling variability.

111. A false or mistaken result obtained in a study or experiment BIAS Fluctuation of and estimate around the population value (RANDOM VARIABILITY) Error due to factorsthat inherent in the design, conduct and analysis Result obtained in sample differs from result that would be obtained if the entire population were studies ERROR SYSTEMATIC ERROR RANDOM ERROR = +

112. Sources of Error Observers Subjects Researchers Administering The measure Bias Random Random Random Bias Bias SOURCES AND TYPES OF MEASUREMENT ERROR

113. SYSTEMATIC ERROR : SELECTION BIAS INFORMATION BIAS CONFOUNDING

114. RANDOM ERROR Is the divergence, due to chance alone, of an observation on an sample from the true population value

115. Different combinations of high and low reliability and validity VALIDITY High High RELIABILITY Low Low High Low

116. Internal and E xternal Validity External Population Target Population Study Sample VALIDITY INT. EXT. Page 120

117. VALIDITY AND RELIABILITY HIGH LOW VALIDITY HIGH RELIABILITY LOW FREQUENCY A B C D

118. A study is valid if its results corresponds to the truth, no systematic error or should be as small as possible VALIDITY :

119. Is the expression of the degree to which a test is capable of measuring what it is intended to measure A study is valid if its results corresponds to the truth, no systematic error and random error should be as small as possible VALIDITY

120. I s the quality of being sharply defined through exact detail. T he repeated assay of a single test specimen typically gives rise to a set of results that differ to a greater or lesser extent from each order. The smaller the differences, the greater the precision of the assay method. Precision :

121. Measurement The procedure of applying a standard scale to a variable or a set of values. (Last, 1988) Terms used to describe properties of measurement : - Accuracy - Validity - Precision - Reliability - Repeatability - Reproducibility

122. is a distorsion in the estimate of effect resulting from the manner in which subject are selected for the study population MAJOR SOUREC OF SELECTION BIAS 1) flaws in the choice of groups to be compared 2) choice of sampling frame 3) loss to follow up or nonresponse during data collection 4) selective survival SELECTION BIAS

123. INFORMATION BIAS is a distortion in the measurement error or misclassification of subject on one or more variables MAJOR SOURCES OF INFORMATION BIAS 1) invalid measurement 2) incorrect diagnostic criteria 3) omissions imprecision 4) other inadequacies in previously recorded data

124. CONFOUNDING MIXING OF EFFECTS The estimate of the effect of The exposure of interest is distorted because it is mixed With the effect of an Extraneous factor

125. COFFEE DRINKING, CIGARETTE SMOKING AND CORONARY HEART DISEASE EXPOSURE (coffee drinking) DISEASE (heart disease) CONFOUNDING VARIABLE (cigarette smoking) CONFOUNDING

126. T he distortion introduced by a confounding factor can lead to overestimation or under estimation of an effect depending on the direction of the association that the confounding factor has with exposure and disease . C onfounding can even change the apparent direction of an effect. Example : Alcohol Smoking Oral cancer

127. E = E = D D

128. E = E = D D

129. Situation in which F is a confounder for a D - E association. Situation in which F is not a confounder for a D - E association. E F D E F D E F D E F D E F D E F D E F D Page 133

130. To be confounding, the extraneous variable must have the following characteristics A confounding variable must be a risk factor for the disease. A confounding variable must be associated with the exposure under study (in the population from which the case derive). A confounding variable must not be an intermediate step in the causal path between the exposure and the disease.

131. - RESTRICTION - MATCHING - STRATIFICATION - MATHEMATICAL MODEL (Multivariate analysis) DESIGN ANALYSIS CONTROL OF CONFOUNDING